let p1 = new Promise((resolve, reject) => {
  setTimeout(() => {
    resolve('hello')
  }, 10);
})
let p2 = new Promise((resolve, reject) => {
  setTimeout(() => {
    resolve('lagou')
  }, 10);
})
let p3 = new Promise((resolve, reject) => {
  setTimeout(() => {
    resolve('I❤️U')
  }, 10);
})

Promise.all([p1, p2, p3]).then(([result1, result2, result3]) => {
  console.log(result1 + result2 + result3)
})